make bitboards public

src/bitboard.rs

@@ -1,22 +1,28 @@
+//! Sets of squares.
+
 use crate::board::*;
 
 use std::iter::ExactSizeIterator;
 use std::iter::FusedIterator;
 
+/// A set of squares.
 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub struct Bitboard(pub(crate) u64);
 
 impl Bitboard {
+    /// Returns an empty bitboard.
     #[inline]
     pub fn new() -> Self {
         Self(0)
     }
 
+    /// Returns `true` if the bitboard is empty.
     #[inline]
     pub fn is_empty(&self) -> bool {
         self.0 == 0
     }
 
+    /// Returns the square in the bitboard with the smallest index.
     #[inline]
     pub fn first(&self) -> Option<Square> {
         let mask = self.0;
@@ -26,6 +32,8 @@ impl Bitboard {
         }
     }
 
+    /// Removes the square in the bitboard with the smallest index and returns it, or `None` if the
+    /// bitboard is empty.
     #[inline]
     pub fn pop(&mut self) -> Option<Square> {
         let Self(ref mut mask) = self;
@@ -37,13 +45,27 @@ impl Bitboard {
         square
     }
 
+    /// Inserts a square in the bitboard.
     #[inline]
     pub fn insert(&mut self, square: Square) {
         self.0 |= 1 << square as u8;
     }
 
+    /// Returns `true` if the bitboard contains the given square.
     #[inline]
-    pub fn trans(&self, direction: Direction) -> Self {
+    pub fn contains(&self, square: Square) -> bool {
+        self.0 & (1 << square as u8) != 0
+    }
+
+    /// Returns the mirror of the bitboard (see [`Setup::mirror`]).
+    #[inline]
+    pub fn mirror(self) -> Bitboard {
+        let [a, b, c, d, e, f, g, h] = self.0.to_le_bytes();
+        Self(u64::from_le_bytes([h, g, f, e, d, c, b, a]))
+    }
+
+    #[inline]
+    pub(crate) fn trans(&self, direction: Direction) -> Self {
         match direction {
             Direction::North => Self(self.0 << 8),
             Direction::NorthEast => Self(self.0 << 9) & !File::A.bitboard(),
@@ -55,17 +77,6 @@ impl Bitboard {
             Direction::NorthWest => Self(self.0 << 7) & !File::H.bitboard(),
         }
     }
-
-    #[inline]
-    pub fn contains(&self, square: Square) -> bool {
-        self.0 & (1 << square as u8) != 0
-    }
-
-    #[inline]
-    pub fn mirror(self) -> Bitboard {
-        let [a, b, c, d, e, f, g, h] = self.0.to_le_bytes();
-        Self(u64::from_le_bytes([h, g, f, e, d, c, b, a]))
-    }
 }
 
 impl std::ops::BitOr for Bitboard {